Petiroc, a New Front-End ASIC for Time of Flight Application

Petiroc is a 16-channel front-end ASIC designed to readout silicon photomultipliers (SiPMs) for particle time-of-flight measurement applications. Petiroc combines a very fast and low-jitter trigger with an accurate charge measurement. The concept of the ASIC is to combine two measurement lines that won't interfere one with another to measure both first incident photon timing measurement and whole crystal light charge integration. An adjustment of the SiPM high voltage is possible using a channel-by-channel input DAC. That allows a fine SiPM gain and dark noise adjustment at the system level to correct for the non-uniformity of SiPMs. The power consumption is 3.5 mW/channel, excluding ASIC outing buffer. First measurement on Petiroc shows a time jitter down to 16ps on 20 photoelectrons test pulses and 46ps with 15 photoelectrons from a Hamamatsu MPPC. Charge measurement has been measured and 1% linearity has been measured up to 2000 photoelectrons. Energy resolution has been measured at 9.5% FWMH. The main application of Petiroc is PET time-of-flight prototyping but can be used for any application that requires both sharp time resolution and precise energy measurement.